Merriam-Webster
Merriam Webster: Dictionary Illustration: Types of Triangles
A labeled illustration of six different types of triangles.
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Properties of Triangles
This lesson focuses on the properties of triangles, a closed shape that has three sides, three vertices, and and three internal angles. There are different types of triangles such as a right triangle, obtuse, and acute based on the...
Oswego City School District
Regents Exam Prep Center: Angles and Triangles
On this site a viewer can learn about the different types of triangles, and categorized by either angles or sides. Tutorials are also included for interior and exterior angles of triangles. A teacher resource page includes a lesson plan...
Mocomi & Anibrain Digital Technologies
Mocomi: Types of Triangles
Explore the different types of triangles and other properties.
Mangahigh
Mangahigh: Shape: Types of Triangle
Test your knowledge of triangles by identifying the different types.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Types of Triangles
Find a quick, concise explanation of the different types of triangles. Examples are given and clearly explained.
Science Struck
Science Struck: List of Different Types of Geometric Shapes
A comprehensive list of 2D shapes and 3D solids with everything from a triangle to a dodecahedron. Includes illustrations and short descriptions of attributes for each.
CK-12 Foundation
Ck 12: Geometry: Triangle Relationships Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide reviews terminology for triangles, triangle properties, different types of triangles, and interior and exterior angle theorems.
Math Is Fun
Math Is Fun: Interactive Triangles
This is an excellent tool for students to explore how changes in the size of a triangle's sides or angles affect its appearance. Different types of triangles and angles are presented.
Math Open Reference
Math Open Reference: Triangle Quiz
Students are assessed on different types of triangles. Definitions of the triangles are included.
Alabama Learning Exchange
Alex: A Triangle to Remember
This lesson will introduce students to different types of triangles by using a clip from the movie A Walk to Remember. They will take part in interactive tutorials to strengthen the concepts of classifying triangles. The students will...
Cuemath
Cuemath: Triangles
Explore everything about triangles. Learn about the different types, important properties, and how to find its area and perimeter. Check out the solved examples and interactive questions for better understanding.
CK-12 Foundation
Ck 12: Geometry: Triangle Classification by Angles
[Free Registration/Login may be required to access all resource tools.] Classify different types of triangles by their angles.
CK-12 Foundation
Ck 12: Geometry: Special Right Triangles Study Guide
[Free Registration/Login may be required to access all resource tools.] Different types of right triangles and trigonometric ratios for special right triangles are covered in this study guide.
E-learning for Kids
E Learning for Kids: Math: Dojo: Polygons and Time Zones
Students will play several learning games to explore polygons such as triangles, and how to determine the area of triangles and the different types of triangles. They will also explore time zones.
Crayola
Crayola: Exploring Triangles.
Here's a great geometry activity to display students' knowledge of the different types of triangles. Provides resources and adaptations to supplement this instructional activity. (To access this lesson plan, you must register with...
Cuemath
Cuemath: Altitude of a Triangle
Explore the world of the altitude of a triangle in this mini-lesson including its definition, altitudes in different types of triangles, formulae, some solved examples, and a few interactive questions for you to test your understanding.
CK-12 Foundation
Ck 12: Geometry: Triangle Classification by Side Lengths
[Free Registration/Login may be required to access all resource tools.] Classify different types of triangles by their side lengths.
CK-12 Foundation
Ck 12: Trigonometry: Law of Sines
[Free Registration/Login may be required to access all resource tools.] Learn how to use the Law of Sines with different types of triangles.
CK-12 Foundation
Ck 12: Geometry: Isosceles Triangles
[Free Registration/Login may be required to access all resource tools.] This concept will teach students the properties of isosceles triangles and how to apply them to different types of problems.
Texas Instruments
Texas Instruments: Constructing Triangles
This activity focuses on the various ways to construct the different types of triangles such as isosceles, equilateral, right, and right isosceles triangles. Students will begin by constructing triangles based on a minimal definition of...
Science Struck
Science Struck: Similarity Statement in Geometry With Examples
Models how to write a similarity statement about different types of triangles and quadrilaterals.
CK-12 Foundation
Ck 12: Triangle Classification
[Free Registration/Login Required] Students will move the vertices to different points to create different obtuse triangles. Click learn more to watch a video demonstration and click challenge me to answer a practice question.
University of Cambridge
University of Cambridge: Maths and Sports: Stadium Sightline
How would you design the seating for an Olympic stadium to give spectators the best view of events? This geometry and modelling activity is designed to be accessible to both GCSE and A-level maths students (Key Stage 4 and Key Stage 5),...